Abstract： [Objective] To assess the predilection age,clinical features,treatment and pognostic factors of primary cutaneous B-cell lymphoma (PCBCL).[Methods] A total of 31 patients with PCBCL were registered in Tianjin Cancer Central Registry from January 1970 to September 2010,and 26 patients had complete medical recortds.A retrospective analysis was conducted on the 26 patients.The following indices were analyzed,including gender,age,body sites of initial involvement,extent of cutaneous involvement,pathological subtypes,metastatic sites,treatment,survival and prognosis.Data were processed with SPSS16.0 software,survival analysis was carried out by using Kaplan-Meier method,univariate analysis of prognostic factors by Log-rank test,multivariate analysis of prognostic faetors by COX proportional hazards model,and variables were selected by Forward LR method.[Results] Clinical manifestafions were atypical in these patients.The ratio of man and women was 1:1.6.Of the 26 cases,12 were primary cutaneous follicle-center lymphoma (PCFCL),8 were primary cutaneous marginal zone lymaphoma (PCMZL),and 4 were PCLBCL,leg type.Follow-up revealed lymph node involvement in 8 patients (4 in cervical nodes and 4 in inguinal nodes),distant metastasis of organs in 3 patients ( 1 in lung and pleura,1 in bone marrow and 1 in central nervous system).Most patients received surgical treatment combined with chemotherapy or chemoradiation.The 5-year overall survival rate was 80.8％(21/26).Statistical analysis showed that the prognosis of PCBCL was associated with histological subtype,lactate dehydrogenase (LDH) level and globulin level,but unrelated to gender,age,site of initial involvement,extent of cutaneous involvement,involvement of lymph nodes and organs,presence of B symptoms,treatment strategies,number of relapses,level of β2-globulin and hemoglobin,or lymphocyte absolute value.[Conclusion]s PCBCL,as a kind of rare extra-nodal lymphoma,usually occurs with atypical clinical mainfestations in persons aged from 39 to 66 years.The 5-year overall survival rate was 80.8％ in these patients.The prognosis of PCBCL seems to be related to histological subtypes,LDH and globulin levels.